Expansion and compression joint particularly for road surfaces



Nov'. 12, 1968 D. M. H. HAMEL 3,410,184

EXPANSION AND COMPRESSION JOINT PARTICULARLY FOR ROAD SURFCES Filed May23, 1966 2 Sheets-Sheet l a F7 .l V g i Kvk I -u 1 IHM-++i NOV. 12, 1968D M, H, HAMEL A 3,410,184

EXPANSION AND COMPRESSION JOINT PARTICULARLY FOR ROAD SURFACES Filed May23, 1965 2 Sheets-Sheet 2 3,410,184 EXPANSION AND COMPRESSION JOINT PAR-TICULARLY FOR ROAD SURFACES Denis Marcel Henri Hamel, Saint-Mande, Valde Marne,

France, assignor to Pneumatiques Caoutchouc Manufacture et PlastiquesKleber Colombes, Colombes,

France, a French body corporate Filed May 23, 1966, Ser. No. 552,056Claims priority, application France, June 4, 1965,

19,750 8 Claims. (Cl. 94--18) ABSTRACT F THE DISCLOSURE An expansion andcompression joint for a road surface layer comprises a metallic caissonformed by two facing channel members one sliding freely and transverselyinto the other, one or both channels having end plates, and resilientmeans between the channels. As protection means against pinching andcreep of the ends of the resilient means, a small tongue extension ofthe end wall of the resilient means is inserted between the side wall ofthe resilient means and the bottom of a channel member supporting it.The resilient means may enclose an air chamber or encase a separateinflatable bladder. The protection means may also be reinforced orharder rubber caps.

The present invention relates to expansion and compression joints whichare inserted between the slabs of concrete structures. These joints areused particularly for road surfaces to maintain the concrete slabs undercompression and thus prevent fissures arising whilst permittingdimensional variations of the slabs due to shrinkage of the concrete orto expansions and contractions of the surface.

These joints are generally placed transversely across the road surfacein the intervals separating adjacent slabs so as to exert a directionalcompression in the longitudinal direction of the surface.

In United States Patent No. 3,106,879, filed January 30, 1961 forExpansion and Compression Joint for Road Surfacing, there are describedexpansion and compression joints comprising resilient air chamber meanssuch as an inflatable bladder contained in the interior of a metalliccaisson constituted by two U-shaped metallic elements engaged one in theother. These two U-shaped elements can penetrate more or less deeply oneinto the other compressing the bladder so as to follow the expansionsand contractions of the slabs. This patent relates more particularly tomeans for preventing the bladder from being pinched between the twoU-shaped sections or from creep, under the effect of the inflationpressure, in the spaces comprised between the two sections. These meansconsist in providing bands of elastic material placed longitudinally inthe interior angles of the larger of the two sections. These bands canbe rigidly fixed to the bladder itself.

Experiment has shown that these longitudinal elastic bands effectivelyprevent the pinching and creep of the bladder over the whole length ofthe bladder but that risks of pinching and creep still exist at the twoextremities of the bladder at the places where the caisson constitutedby the two sections is closed by end plates joined to the ends of one ofthese sections. The interposition of rubber plates between the faces ofthe extremities of the bladder and the plates of the extremities of thecaisson do not always eliminate these risks.

It is therefore an object of the invention, to protect the extremitiesof the bladder in order to eliminate more completely the risks ofpinching and of creep of the bladnted States Patent O ACC der in itsparts corresponding to the extremities of the metallic caisson whichcontain it. j

This protection can be effectedv by extending each wall of the end ofthe bladder by a small rubber tongue turned between the bottom of one ofthe ridged sections constituting the metallic caisson and theside wallof the bladder resting on this bottom. i

In alll cases, the resilient air chamber means or bladder can be airtight and itself contain air under pressure or better, can be anon-impervious elastic envelope contain- 'ing a separate inflatableair-chamber. In the last case the bladder at the reinforced end can bereduced to simple caps covering only the ends of the air-chamber to beprotected.

The invention relates also to a process for the manufacture of bladderswith reinforced ends characterised in that there is made separately acentral body of the bladder by extrusion and parts of the reinforcedends by moulding and the central body and the reinforced ends arejoined.

Several embodiments by way of non-limiting examples of the invention aredescribed below with reference to the accompanying drawings in which:

FIGURE 1 is a view in transverse section of a joint in accordance withthe present invention, between two slabs of concrete of a road surface,the plane of the section being taken in the central part of the joint sothat the form of this transverse section can apply to variousembodiments of the invention shown by the other figures,

FIGURE 2 is a view from above of a section along the horizontal planea-a of FIGURE 1; and

FIGURE 3 is a perspective view showing the reinforced end of the bladderof FIGURE 2.

Referring now to FIGURE` 1, it is seen that the assembly of the jointcomprises a deformable metallic caisson constituted by two U-formsections 7 and 8, which can slide transversely one into the other.Inside this metallic caisson is placed an elastic bladder 13 in the formof a hollow beading. This elastic bladder contains an air chamber 14inflatable by a valve situated preferably at an end of the joint.

In the mounted position the joint extends across the road between twoadjacent slabs of concrete 2 and 3, which rest on the foundation 1 andis supported by the faces of the ends of these slabs by intermediarymetallic plates 4 and 5.

The interior section 7 is engaged fairly deeply in the exterior section8 but of course there is provided a suicient play to enable theexpansion of the slabs 2 and 3.

The bladder 13 comprises longitudinal lips 131 and 132 situated so as tobe just placed in the interior angles set into exterior section 8,opposite the edges 71 of the Wings of the interior section 7.

When the air chamber 14 is inflated, the lips 131, 132 of the elasticbladder assume their place in the reentrant angles of the section 8 andthey substantially fill the free space comprised between the bottom ofthe section 8 and the edge 71 of the wings of these interior section 7.They avoid the bladder 13 having its wall folded back in the spaces andfrom being nipped between the two sections.

In the case of FIGURES 2 and 3, the ends of the bladder 13 are,according to the invention, reinforced by means of a rubber tongue 20,made in one piece with the bladder. This tongue 20 extends on one sidethe end wall 21 of the bladder 13 and it is folded back between the sidewall of the bladder and the bottom of the interior section 7. It issufciently thick to form a shield preventing the bladder from beingnipped or from creep in the clearance 22 comprised between the end plate11 jointed at the end of the section 8 and the face of the end of thesection 7 under the effect of the inflation pressure of the air chamber.The end of the small tongue 20 can be tapered to ensure a progressivejoining up of the superimposed walls.

When the bladder is used with an interior air chamber 14, the end wall21 of the bladder is partly cut out by a slit 23 (FIGURE 3) enabling theintroduction of the air chamber. When, on the other hand, the bladder 13is used without an air chamber, this slit is omitted and the end wall 21is hermetically joined to the body of the bladder.

Finally, the ends of these Abladders can be further reinforced by usingfor their ends, rubber mixtures more resistant to stretching than thatconstituting the central body of the bladders.

When the bladder 13 is used as a protective envelope, for an interiorair chamber 14, it has no need to be tight and can then be constitutedby separate elements, namely a central part 13a, and end parts 13b, thelatter being suitably reinforced. These various parts are simply closedaround the air chamber. In a further embodiment` the bladder can benarrowed at the single parts of the ends 13b, having the form of capsreinforced as described above and covering only the ends of the airchamber to protect it from creep and from pinching by the ends of thecaisson.

When the bladder 13 is on the other hand, used in an air chamber andwhich mustbe tight, the parts 13a, and 13b, must then be joined forexample by vulcanised joints.

In the two cases, there are advantageously used the process ofmanufacture consisting of forming the central body of the bladder byextrusion of a hollow beading of the desired profile whilst thereinforced ends are constructed and moulded separately. The differentparts are then joined along transverse junction lines 28as indicated inFIGURE 2. The body being capable of being cut to a desired length in asection of great length, it is then easy to obtain bladders ofappropriate dimensions for joints of different lengths.

It will be understood that the invention is not limited to the aboveembodiments from which one can conceive other variants of execution,combining different characteristics described.

I claim:

1. An expansion and compression joint for road surface layers and thelike, comprising a metallic caisson nel Amerhbers towards and away fromeach other, ,and at least the larger channel member `having end platesclosinglthe inner` space of the caisson, a pair of longitudinal ribsprovided to extend between the end of the smaller channel anges and thebottom of the larger channel member," inflatable resilient casing meansenclosed in the caisson and in contacting relationship with the innersurfaces of said caisson, the end walls of said casing means engagingthe end plates of the larger channel member and extended by a tongueinserted between the bottom'of said smaller channel member and the sidewall ofthe casing means supported against said bottom.

2. A joint according to claim 1, wherein said longitudinal ribs areunitary with the inatable casing.

3. A joint according to claim 1, wherein said casing consists of acentral body and end members in form of separate caps engaging said endplates.

4. A joint according to claim 1, including an inatable tube enclosed insaid casing.

5. A joint according to claim 2, wherein said casing consists of acentral body and end members in the form of caps engaging said endplates.

6. A joint according to claim 2, including an inflatable tube enclosedin said casing.

7. A joint according to claim 5, including an inflatable tube enclosedin said casing.

8. A joint according to claim 5, including an inllatable tube enclosedin said casing.

References Cited UNITED STATES PATENTS 3,106,879 10/1963 Hamel 52396 XRFOREIGN PATENTS 78,191 5/1962 France.

JACOB L. NACKENOFF, Primary Examiner.

